CVE-2026-91122

Source
https://cve.org/CVERecord?id=CVE-2026-91122
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-91122.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-91122
Aliases
  • GHSA-8m44-f6g9-7cg7
Published
2026-09-24T16:56:26Z
Modified
2026-09-26T03:48:26Z
Severity
  • 8.7 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N CVSS Calculator
Summary
Discourse: Chat MessageBus delivers read-restricted messages to unauthorized users
Details

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the video placeholder component allowed crafted HTML to cause an attribute breakout and inject an attacker-controlled event handler. An authenticated user with default trust-level posting privileges could store the crafted placeholder in a post. When another user opened the post and clicked the video play overlay, the handler could execute arbitrary JavaScript in the viewer's session. Default Content Security Policy settings block inline event handlers, but instances with CSP disabled or relaxed could allow the script to read page content and make authenticated requests as the viewer. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.

Database specific
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-79"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91122.json"
}
References

Affected packages

Git / github.com/discourse/discourse

Affected ranges

Type
GIT
Repo
https://github.com/discourse/discourse
Events
Database specific
Show details
{
    "extracted_events":  [
        {
            "introduced":  "0"
        },
        {
            "fixed":  "2026.8.0"
        },
        {
            "introduced":  "2026.7.0-latest"
        },
        {
            "fixed":  "2026.7.2"
        },
        {
            "introduced":  "2026.6.0-latest"
        },
        {
            "fixed":  "2026.6.3"
        },
        {
            "introduced":  "2026.1.0-latest"
        },
        {
            "fixed":  "2026.1.8"
        }
    ],
    "source":  [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

Other
_gh-attach-assets
esr
stable
v2026.*
v2026.1.0
v2026.1.0-latest
v2026.1.1
v2026.1.2
v2026.1.3
v2026.1.4
v2026.1.5
v2026.1.6
v2026.1.7
v2026.6.0
v2026.6.0-latest
v2026.6.1
v2026.6.2
v2026.7.0
v2026.7.0-latest
v2026.7.1
v2026.8.0-latest
v2026.8.0-latest.1

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-91122.json"